Switching device for radio and phonograph combinations



June 30, 1931. M. B. LONG 1,811,856

swncame msvxca FOR mum AND raonoemrn dousmnxons Original Filed Oct. 1, 192a /NVENTOR Mamas/5mm;

ATTORNEY Patented June 30, 1931 UNITED STATES PATENT OFFICE MAURICE B. LONG, OF GLEN RIDGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SWITCHING DEVICE FOR RADIO .AN'D PHONOGRAPH COMBINATIONS Original application filed October 1,1926, Serial No. 138,854. Divided and this application. filed May 26,

This invention relates to sound reproducing apparatus and particularly to radio and phonograph combinationsand is a dlVlSlOI]. of application, Serial No. 138,854, filed October 1, 1926.

An object of the invention is to provide means whereby amplifying and reproducing apparatus may be readily associated with a mechanically operated electrical pick-up device or an electrically operated pick-up device.

In a specific preferred embodiment this invention comprises an electrical pick-up device adapted to be mechanically operated by a phonograph record and an electrical pick-up device such as a radio receiver, both of which are adapted to be separately associated with common amplifying equipment by means which are automatically controlled by the phonograph operating mechanism to bring about the alternative connection and disconnection of the two pick-up devices with the amplifying apparatus.

The present invention provides a greater selection of entertainment, or a practically uninterrupted form of entertainment, at the will of the operator. This invention provides means whereby the act of bringing into service the phonograph will disassociate the radio circuit from the amplifying and reproducing equipment, and the act of discontinuing the operation of the phonograph will cause its disassociation from the amplifying and reproducing equipment and cause the latter to be associated with the radio circuit. It will be understood that the amplifier may be dispensed with if sufiicient volume of reproduction is obtained without it.

The invention will be clearly understood from the following detailed description, taken in connection with the drawing in which there is diagrammatically shown one embodiment of the invention.

In the drawing there is shown an antenna circuit, comprising an antenna 5, an inductance 6, and three optional or alternative paths to ground from inductance 6. Relays 7 and 8, controlled by keys or push buttons 9, 10, 11 and 12, are adapted to connect any Serial No. 194,342.

or alternatively connected in circult by the relays 7 and 8 under control of the keys 9, 10, 11 and 12.

The radio receiver in addition to the circuits described above, comprises an electric space discharge detector tube 24 feeding an electric space discharge amplifier tube 25 through an audio frequency transformer 26, having one terminal of its secondary winding connected through the left hand contact of an electromagnetic switch 27 to the grid of tube 25, an electric space discharge amplifier tube 28 fed from tube 25 through an audio frequency transformer 29', and a loud speaking telephone receiver 30 fed from tube 28 through a transformer 31, having one terminal of its secondary winding connected through the right hand contact of an electromagnetic switch 32 to an adjustable volume control or voltage changing device 33. As indicated by conductors 34, other volume control devices and loud speakers, located at different desired points, maybe connected to the output side of transformer 31.

When the relay 42 is ener 'zed to throw its armature into the right and position, a battery 40 supplies heating current to the filaments of tubes 24 and 25 through the following circuit. From the positive terminal of battery 40 through the left hand contact of a relay 42, left hand contact of relay 32, filament of tube 25, filament of tube 24, and a resistance to the negative terminal of battery 40.

Steady otential for the grid of tube 25 is supplied by the voltage drop in the filament of tube 24 and resistance 45.

An alternating current source 46 supplies current to the primary winding of a transformer .47 and supplies current to the primary winding of a transformer 48 and the primary winding of a transformer 49 through the right hand contact of relay 42. The secondary winding of the transformer 47 supplies current for operating relays 7, 8, 42 and 32 under the control of keys 9, 10, 11 and 12.

A secondary winding 50 of transformer 48 has its mid-point grounded and supplies alternating current for heating the filament of tube 28.

Alternating current from a secondary winding 51 of transformer 48 is rectified in a circuit extending from the left hand terminal of winding 51 through choke coil 52, resistances 55, 56 and 57 to ground, thence through conductor 60, resistance 65, conductor 66, the space discharge path of an electric space discharge rectifier tube 67 to its cathode, and thence to the right hand terminal of winding 51. A portion of winding 51 supplies alternating current for heating the filament of rectifier tube 67. The voltage drop in resistance is applied as a steady potential to the grid of tube 28, through a resistance 68 and the secondary winding of transformer 29.

The voltage drop across resistance 57 is applied as a steady potential to the plate of tube 24, through the primary winding of transformer 26.

The voltage drop across resistances 56 and 57 is applied as a steady voltage between the plate and the filament circuit of tube 25, through the primary winding of transformer 29.

The voltage drop across resistances 55, 56 and 57 is applied as a steady voltage between the plate and the filament circuit of tube 28,

through the primary winding of transformer 31.

The choke coil 52 and a condenser 70 reduce voltage fluctuations across resistances 55, 56, 57 and 65. A condenser 71 further reduces voltage fluctuations across resistances 55, 56 and 57. A condenser 72 further reduces voltage fluctuations across resistances 56 and 57. A condenser 73 further red lzlces voltage fluctuations across resistance 5 senting conductors leading from the set of.

keys 9, 10, 11 and 12, this set of keys may,

if desired, be remote from the condensers 15, 16, 17, 15, 16', and 17, which they control. For example this set of keys may be located at a loud speaking telephone receiver (not shown) connected to the conductors 34 at a distance from the condensers, the tubes 24, 25 and 28 and the loudspeaker 30.

As indicated by conductors 75, other sets of keys (not shown) like the set constituted by keys 9, 10, 11 and 12 may be employed, the keys 9, 10,11 and 12 being connected in multiple with the corresponding keys,r.re spectively, of each of such other sets. Such other sets may be located at any desired places. :For example, one set'may be near the tuning condensers and the loud speaker 30.

Pilot lamps such as 76 are connected to the secondary winding of transformer 49, the primary Winding of which is connected directly in parallel with the primary winding of transformer 48. Each of these lamps may be located, whenever desired, to indicate whether the source 46 is supplying E. M. F. to the transformer 48.

The armature of each of the relays 7, 8

and 42, in the absence of current in the windings of the relay, is held in the position to which it was last operated by one of its windings. A holding spring is shown for each of these relays, to represent means for thus holding the armature.

The winding of relay 32 is directly in series with the secondary winding of transformer 47. Relay 32 is therefore momentarily operated whenever one of the keys 9 to' 12 1s momentarily operated, or in other words, whenever either of the windings of relay 7, 8 or 42 is'energized. When the relay 32 is energized, it quickly opens its right hand contact, to disconnect from the second-.

ary winding of transformer 31 the volume control devices and loud speakers such as 33 and 30, and thereafter opens at its right hand contact the filament heating circuit of tubes 24 and 25. When the relay 32 is deenergized, it first closes its left hand contact and thereafter closes its right hand contact. Operation of the relay 32, therefore, prevents the production of noise in the loud speakers, due to the action upon the input circuits of tubes 24 and 25 of stray field from the windings of relay 7, 8 and 42 when those windings are switched in or out of circuit b keys 9 to 12. The relay opens the circuit of the secondary winding of transformer 31 before the stray field has time to change materially, and the cooling of the filaments of tubes 24 and 25, due to the opening of the filament circuit at relay 32, renders the tubes inoperative until the stray field has again reached a substantially steady state.

Each of the coils 18, 19 and 20 is, independently of the others, variably coupled to the coil 22.

' b To condition or adjust the system so that itma substantially instantaneously be set to se ectively receive signals transmitted, on waves of any of three different wave lengths, for example, signals from three broadcasting stations J, K and L (not shown) from "which it will be desired to receive signals more often than from other stations, key'9 may first be closed momentarily. Thereupon, the left hand winding of relay 7, the right hand winding of relay 42 and the winding of relay 32 are energized over the following circuit.- From the right hand terminal of the secondary winding of transformer 47 through the Winding of relay 32, key 9, a resistance 79, left hand winding of relay 7,'and right hand winding of relay 42. Relay 32 operates momentarily. Relay 7 operates to throw its armature to the left, or remains operated, with its armature in the lefthand position, remaining in that position after key 9 is released. Relay 42 operates to throw its armature to the-right or remains operated with its armature in the right-hand position, remaining in that position after key 9 is released.

With the armature of relay 42 in the right hand position, the filament circuit of tubes 24 and 25 and the circuit of the primary windings of transformers 48 and 49 are closed at its contacts.

With relays .7 and 42 operated as describe above, the antenna circuit extends from antenna 5 and coil 6 through the outer left hand contact of relay 7 condenser 15 and coil 18 to ground, and the condenser 15 is connected across the coil 22 by theinner right hand contact of relay 7. Condenser 16, 17, 16 and 17 and coils 19 and 20 are then out of circuit. By adjusting condensers 15 and 15 the system can be tuned to the wave length of station J, for example, and the coupling between coils 18 and 22 may be adjusted in accordance with the intensity of the wave received by antenna 5 from station J. The system is then conditioned for receiving signals from station J,

and, thereafter, whenever the operator has changed it to a condition for receiving signals of other wave lengths or to a condition in which it is not responsive to signals of any wave length, it can substantially instan taneously be conditioned for receiving signals from station J by momentarily actuating key 9. p

, Thev system having been conditioned so that it can substantially instantaneously be set to selectively receive from station J,

it may next be conditioned so that it can similarly be set to receive from station K. This is done by first momentarily closing key 10 and then adjusting condensers 16 and 16 and the coupling between 19 and 22, as was done previously for the other elements. vSimilarly,"by momentarily pressing key 11 and by adjusting condensers 17' and,

17' and coupling 20-22, the system may 7 be conditioned to receive from station L. I At any time, the system may be rendered unresponsive to signals of any wave length by depressing key 12 momentarily, whereby there is established momentarily a circuit extending from the secondary winding of transformer 47 through relay 32, key 12, a resistance 80, and left hand winding of relay 42. Upon establishing this circuit,

relay 32 is operated momentarily, and relay the same constants and yet receive the same value of operating current" from transformer 47. Resistance 79 has an absolute impedance substantially equal to that of one of said windings, and the impedance of resistgnee 80 is twice theimpedance of resistance A phonograph has a reproducer 86 and has a start-stop mechanism represented, by way of example, by a brake 87. The start-stop mechanism, when in position to prevent motion of the phonograph turntable, opens aswitch 89 to maintain relay 27 deenergized. The grid or input circuit of tube 25, including the primary winding of transformer 26, is therefore, closed at the left hand contact of relay 27 and the radio receiver is operative to reproduce signals from the wave received by antenna 5.

-When the start-stop mechanism is in position to allow the phonograph to operate, switch 89 is closed, and, provided relay 42 is closed to the right, relay 27 will be energized over a circuit extending from battery 40 through left hand contact of relays 42 and 32, winding of relay 27, and switch 89, to battery 40.

Energization of relay 27, in the manner just described, disconnects the secondary 'winding of transformer 26 from the input electrodes of tube 25, so that the radio recelver W111 not operate to reproduce signals carried by the wave incident upon antenna- 5, during the time that the phonograph is which is of the electrical type is connected to the primary winding of a transformer 90,

the secondary winding of which is adapted to be connected between the grid and the filament of tube 25 by a front contact on relay 27. Thus, when the phonograph is operating, output from the electrical pick-up device 86 is amplified by tubes 25 and 28 and converted into sound by loud speakers, such as 30.

What is claimed is:

1. In combination, a radio receiver, a phonograph having an electrical reproducer and record actuating means, start-stop mechanism for the latter, a sound reproducer, and a switch for connecting said radio receiver and said electrical reproducer to said sound reproducer alternatively, said switch being connected to said start-stop mechanism and operated in the normal operation of said start-stop mechanism.

2. In combination, a phonograph, a radio receiver, a loud speaking element, and means actuated by the initiation of operation of the phonograph to switch said loud speaker from the radio receiver to the phonograph and actuated by the cessation of operation of the phonograph to switch said loud speaker from the phonograph to the radio receiver.

3. In combination, a phonograph, a radio receiving set, an electric reproducer for said phonograph, start-stop mechanism to control the operation of said phonograph, a loud speaking element, and switching means 'actuated by the start-stop mechanism of said phonograph to connect said reproducer to the loud speaking element when the startstop mechanism is in the start position and to connect the radio set to the loud speaking element when the start-stop mechanism is in the stop position.

4. In combination, a radio receiving set, an electric reproducer operated by a phonograph record, an amplifier of electrical waves, means for converting the electrical waves into sound waves connected to said amplifier, and means actuated by the initiation of operation of the phonograph to switch said amplifier and said means connected thereto from the radio receiving set to the phonograph reproducer, and actuated by the cessation of operation of the phonograph to switch said amplifier and said means connected thereto from the phonograph reproducer to the radio receiving set.

5. In combination, a radio receiving set, a phonograph, and electro-magnetic reproducer for the phonograph, start-stop mechanism to control the operation of said phonograph, an electrical amplifier, a loud speaking element attached thereto, and switching means actuated by the phonograph start-stop mechanism to connect said electro-magnetic reproducer to said amplifier when the phonograph'start-stop mech- [i anism is in the start lposition and connect said radio receiver to t e amplifier when the phonograph start-stop mechanism is in the stop position.

6. In a sound reproducing system, a mechanically operated electrical pick-up device, an electrically operated pick-up device, amplifying apparatus for amplifying the electrical waves from either of the two pickup devices, and switching means automatically operated by bringing one pick-up device into service for associating it with the ampl1fy1ng equipment and disassociating the other pick-up device therefrom, and by cutting the first mentioned pick-up device out of service for disassociating it from the amphfying equipment and associating-the other pick-up device therewith.

7. In combination, a signal receiving system, means operable for rendering sa1d rece1v1n system inoperative, a phonogra h turnta le, means 0 erable for initiating t e operation of said p onograph turntable, and means so connecting said first two means that operation of the means for initiating the operation of the phonograph turntable causes the operation of the means for renderinp the receiving system inoperative.

8. n combination, an electric phonograph, a radioreceiver, an audio-frequency amplifier, and automatic switching means operated by an essential operation in starting said phonograph for connecting said amplifier to said phonograph and operated by an essential operation in stopping said phonograph for connecting said amplifier to said radio receiver.

9. The combination according to claim 8 in which the automatic switching means is operated by the turntable starting device.

10. In a combined radio receiver and electric phonograph having a common loud speaker device, a common audio frequency amplifier-and a rotatable table, thecombinatlon of a brake to control the rotation of said table, and means operable with said brake selectively to connect said loud speaker device to the phonograph or to the radio relacfeiiver through said audio frequency am p 1 er.

11. In combination, a radio receiving set having a detector, an audio frequency amplifier, a phonograph device having an electrical pick-up and a rotatable table to support the record played by said phonograph device, a brake to control the rotation of said table, and means operable with said brake selectively to connect either said pick-up device or said detector to said amplifier.

12. In combination, a phonograph device having an electrical pic -up arrangement, a radio set having audio amplifiers and a loud speaker, combined switch and brake means for starting the phonograph device and connecting the loud speaker to the pickup arrangement through the audio amplifier, or stopping the phonograph device, and

the said connections and redisconnectin he audio amplifier to the radio connecting t set.

13. In combination, a radio receiving set having a detector, an audio frequency amplifier, a honograph device having an electrical pic -up and a rotatable table to suport the record played by said phonograph evice, a brake to control the rotation of said table, and means operable by the movement of said brake. selectively to connect either said pick-up device or said detector to said amplifier.

In witness whereof, I hereunto subscribemy name this 25th day of May, A. D., 1927.

MAURICE B. LONG. 

